Method of salvaging reamers or like tools.



SIA. c0 DILL.

METHOD OF SALVAGING REA MERS 0R LIKE TOOLS.

APPLICATION HI. MAY

Patented May 28, 1918.

STUART A. COGSDILL, 0F DETROIT, MICHIGAN, ASSIGNOR TO DETROIT REAMER SALVAGE 00., OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

Specification of Letters Patent.

rammed May as, 1918.

Application filed May 21, 1917. Serial No. 169,898.

To all whom it may concern:

Be it known that I, STUART A. CoosDILL, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan have invented certain new and: usefulg Improvements in li Iethods of Salvaging ,Reamers -.or like Tools, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a method of salvaging reamers which have become worn down or broken in use and refers more particularly to the method of restoring and recentering reamers or like tools, such as drills or the like.

When tools of this type become worn or particularly when they become broken, it is customary to discard them.

The present invention contemplates a method whereby the worn or broken reamers may be salvaged and made just as suitable for use as new reamers. The invention also contemplates a method in which the reamer can be re-centered and re-ground without the employment of extraneous devices; to provide a method in which the reamer is accurately ground by using the new center as v the axis about which it is moved in retrimming or re-grinding; to provide a method whereby worn or broken reamers can be restored to operative condition at slight expense; and in general to provide a new and improved method for salvaging reamers or the like.

In the drawings:

Figure 1 represents a broken reamer to be salvaged;

Fig. 2 represents a method of grinding the male center on the end of the reamer;

Fig, 3 illustrates the manner in which the flutes are salvaged;

Fig. 4 illustrates the reamer of Fig. 3 completed;

Fig. 5 is a fragmentary View showing the modified method of grinding the male center of the reamer.

Describing in detail the improved method and referring to the drawings in which the manner of carrying out this method is illustrated; A designates a reamer which, as shown in Fig. 1, has been broken, as indicated at B, in use. If the reamer is so broken it is necessary to grind the end of the reainer to the line designated by C in order for aproper cutting end to be formed on the reamer. In grinding this end to the line C, I perform the operation in such a manner as to provide a male center I). This may be accomplished in various ways; thus in Fig. 2 it is shown by employing a grinding periphery E for cutting down the main portion of the reamer by moving it inward to the line E, indicated in dotted lines, and then forming the male center D by moving a grinding wheel F having abeveled periphery F inwardly to the position shown in dotted lines.

A still further method, and one which in many cases is preferable because of its simplicity, consists in arranging a cylindrical shaped grinding member G with its axis inclined to that of the reamer, as indicated in full lines in Fig. 5, and then causing it to travel inward to the position shown in dotted lines. This arrangement has the advantage of both grinding off the main body portion and simultaneously forming the male center D.

When the reamer is broken, as indicated in Fig. 1, the fluted portion is necessarily materially shortened as the forward end of the reamer is ground down. In some instances this shortening of the fluted portion of the reamer would make the latter unfit for use. I, therefore, grind the flutes H back a suflicient distance, as indicated in Fig. 3, to provide the necessary length for this portion of the reamer. This operation, of course, is not necessary where the forward end of the reamer does not have to be ground down to a material extent.

In the usual construction of reamers the forward portion of the flutes, which is designated by H, are of greater diameter than the intermediate or plain surface of the reamer, designated by J It therefore becomes necessary to restore these surfaces after the fluted portion is lengthened by grinding to the same relative proportions employed in the original tool. To accomplish this result after the center is formed on the reamer, I grind down the plain surface, designated by J, until it is of lesser diameter than the fluted section H. The fluted portion is then ground down to provide proper proportioning and in this operation the fluted portions are provided with suitable cutting edges as will be readily understood. In both cases the device inbeing re-ground is centered about the new male center and the original center K on the tang end of the reamer and thus the cutting edges will be automatically positioned with reference to the male center.

While the diameter of the reainers will be somewhat lessened Where it is necessary to re 'rind the fluted portion, the only clifterence in the salvaged reamer will be in the size, the reanier being, however in all respects equal to the original rcamer before broken. While I have described'the invention in connection with reamers, in its broader aspects it is not limited to the particular tool mentioned as it is also applicable to salvaging drills or other tools of this same general character.

Vhat I claim as my invention is 1. The method of salvaging reamers or like tools which comprises cutting down the tool to form a male projection on the cutting end thereof and using the projection thus formed as a centering device While regrinding the tool.

The method of salvaging reamers having a plain body portion and fluted portion of greater diameter than the body portion which comprises arranging a grinding periphery so that it will cut down the end of the reamer beyond the Worn or broken portion and leave a male centering devicecutting back the fluted portion to secure the necessary length of the cutting edges and re-grinding the cutting surfaces of the reamer so that its axis corresponds to the new male center.

In testimony whereol I affix my signature.

STUART A. COGSDILL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents,

Washington, D. G. 

